1. Field of Invention
The invention relates to a semiconductor chip, and particularly to a semiconductor chip with a post-passivation scheme formed over a passivation layer.
2. Description of Related Arts
The Au bumps are used for the TCP (tape carrier packaging) and COG (chip on glass) assembly in the LCD driver ICs. Due to the finer pixel demand and ever-increasing panel size, the required number of I/O layouts is increasing. In the conventional design, referring to FIG. 1, the chip 101 includes a single row of IO contact pads 102 exposed by openings in a passivation layer. The IO contact pads 102 are at the periphery of the chip 101. Au bumps 103 are formed on the 10 contact pads 102. There are no semiconductor devices, such MOS devices or transistors, under the IO contact pads 102.
With the increasing of the number of the IOs, the size of the Au bumps 103 have to be shrunk to maintain the chip 101 in a small size. Then it becomes technically difficult and economically expensive in connecting the chip 101 to an external circuitry.
Some designers design the contact pads 202 of the chip 201 aligned in two rows, as shown in FIGS. 2 and 3, with the contact pads 202 exposed by openings in a passivation layer 204. There are no semiconductor devices 205, such MOS devices or transistors, under the contact pads 202 and Au bumps 203, neither. Then the chip 201 cannot be maintained in a small size since the underlying semiconductor substrate 206 vacates a peripheral region 207 having no semiconductor devices.